Researchers at Bletchley Park's National Museum of Computing have announced the completion of a replica code-breaking machine used by the Allied forces in World War II. Taking three years to complete, the Tunny machine is part of a new exhibition that opened at the museum on Thursday.
The Tunny machine represents an important milestone in Britain's military efforts in World War II. Bletchley Park cryptographers at the time had no access to the Lorenz cipher machines used by the Germans to encrypt their messages. Their big breakthrough came on August 30th, 1941, when a German operator mistakenly sent the same message (bar a few alterations) twice using the same key settings. By the end of the war, 15 Tunny machines were in operation, cracking in the region of 300 messages per week.
Much like the original inventors, researchers had very little to work with to recreate the historic machine. Following the end of the war, the British army ordered the destruction of the machines. The team had to use any resources available to them, from photos taken, to bits of old circuit diagrams, and even the recollections of the system's engineers.
The effort involved in recreating the machine is phenomenal, but John Whetter, one of the team leaders, believes the project holds great importance. Speaking to ZDNet, Whetter said "we are leaving [the Tunny machine] as a legacy and a tribute to those legends at Dollis Hill [Post Office Research Station] and Bletchley Park who never got the recognition they deserved."